Question

I saw some examples giving boundary class like LoginForm etc. That sounds correct at first glance. But in a real app where I have CRUD (4 functions at min) for each Model/Entity, isit more correct to group all functions for a single entity into 1 class?

eg.

<<Boundary>>    
TransactionForms
================
+ insertTransaction(...)
+ updateTransaction(...)
+ deleteTransaction(...)
+ listTransactions()

Answer 1

It would be better to have something like below for boundary objects,

FormService
 + insert(..)
 + update(..)
 + list(..)
 + delete(..).

Internally, those methods make use of Transaction service to update persistent layer.

TransactionService
  + invoke(...)